From 01b8535c5e66b50a503569bb27d7bc3a61e06fff Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Tue, 16 Jul 2024 11:17:45 -0400
Subject: [PATCH] Highlight numbers properly

---
 README.md         |  5 +++--
 src/common/fns.ts |  9 +++++++++
 src/common/row.ts | 21 ++++++++++++++++++---
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index f6f7e37..244f71b 100644
--- a/README.md
+++ b/README.md
@@ -14,8 +14,9 @@ To simplify running, I'm using [Just](https://github.com/casey/just).
 - Deno: `just deno-run [filename]`
 - TSX: `just tsx-run [filename]`
 
-Alternatively, there are shell scripts for each runtime in the `bin` folder. 
-So you can run the editor by calling `./bin/deno.sh [filename]` without installing Just.
+Alternatively, there are shell scripts for each runtime in the `bin` folder. So
+you can run the editor by calling `./bin/deno.sh [filename]` without installing
+Just.
 
 Deno is generally used for dev tools, but each runtime should be functionally
 equivalent running the text editor.
diff --git a/src/common/fns.ts b/src/common/fns.ts
index 9e95888..8e651c4 100644
--- a/src/common/fns.ts
+++ b/src/common/fns.ts
@@ -179,6 +179,15 @@ export function isControl(char: string): boolean {
 	return isAscii(char) && (code === 0x7f || code < 0x20);
 }
 
+/**
+ * Is the one char string a common separator/operator character
+ *
+ * @param char - a one character string to check
+ */
+export function isSeparator(char: string): boolean {
+	return /\s/.test(char) || char === '\0' || ',.()+-/*=~%<>[];'.includes(char);
+}
+
 /**
  * Get the key code for a ctrl chord
  *
diff --git a/src/common/row.ts b/src/common/row.ts
index 811616e..d143276 100644
--- a/src/common/row.ts
+++ b/src/common/row.ts
@@ -1,7 +1,13 @@
 import Ansi from './ansi.ts';
 
 import { SCROLL_TAB_SIZE } from './config.ts';
-import { arrayInsert, isAsciiDigit, strChars, strlen } from './fns.ts';
+import {
+	arrayInsert,
+	isAsciiDigit,
+	isSeparator,
+	strChars,
+	strlen,
+} from './fns.ts';
 import { highlightToColor, HighlightType } from './highlight.ts';
 import Option, { None, Some } from './option.ts';
 import { SearchDirection } from './types.ts';
@@ -240,8 +246,11 @@ export class Row {
 			}
 		}
 
+		let prevIsSeparator = true;
 		let i = 0;
 		for (; i < this.rsize;) {
+			const prevHighlight = (i > 0) ? highlighting[i - 1] : HighlightType.None;
+
 			// Highlight search matches
 			if (word.isSome()) {
 				if (matches.includes(i)) {
@@ -254,14 +263,20 @@ export class Row {
 				}
 			}
 
-			// Highlight other syntax types
+			// Highlight numbers
 			const ch = this.rchars[i];
-			if (isAsciiDigit(ch)) {
+			const isNumeric = isAsciiDigit(ch) &&
+				(prevIsSeparator || prevHighlight === HighlightType.Number);
+			const isDecimalNumeric = ch === '.' &&
+				prevHighlight === HighlightType.Number;
+			const isHexNumeric = ch === 'x' && prevHighlight === HighlightType.Number;
+			if (isNumeric || isDecimalNumeric || isHexNumeric) {
 				highlighting.push(HighlightType.Number);
 			} else {
 				highlighting.push(HighlightType.None);
 			}
 
+			prevIsSeparator = isSeparator(ch);
 			i += 1;
 		}